CK-MB Release Research Articles

TCT-626 Clinical Impact of Troponin and CK-MB Release After Percutaneous Coronary Intervention With Rotational Atherectomy: Results From a Large Prospective Registry

TCT-626 Clinical Impact of Troponin and CK-MB Release After Percutaneous Coronary Intervention With Rotational Atherectomy: Results From a Large Prospective Registry

Cardiac progenitor cells-derived exosomes alleviate myocardial injury by regulating Treg cell differentiation through the mTOR pathway in mice with myocardial infarction

To investigate the effect of cardiac progenitor cells-derived exosomes (CPCs-Exo) on Treg differentiation in mice with myocardial infarction (MI). Mouse models of MI established by ligation of the left anterior descending coronary artery (LAD) were treated with CPCs-Exos, and naive CD4+T cells were isolated from the spleen of the mice and divided into control group, CD4+T cell activation group (CD3+CD28), CPCs-Exos stimulation group (CD3+CD28+CPCs-Exos), mTOR activator group (CD3+CD28+CPCs-Exos+mTOR activator) and mTOR inhibitor group (CD3+CD28+CPCs-Exos+mTOR inhibitor). Western blotting was used to detect the expression levels of mTOR and p-mTOR in the treated cells. Flow cytometry was used to analyze the percentages of Treg and CD4+IL-10+T cells. The infarct size of the mice were measured with 2, 3, 5-triphenyltetrazole chloride (TTC) staining, and serum levels of LDH and CK-MB were detected using an automatic biochemical analyzer. Compared with the control group, the mouse models of MI showed significantly increased release of LDH (P<0.001) and CK-MB (P=0.0002) and increased percentages of Treg and CD4+IL-10+T cells. Treatment with CPC-Exos effectively reduced the MI area and lowered serum levels of LDH (P=0.003) and CK-MB (P=0.003) and the percentages of Tregs (P=0.001) and CD4+IL-10+T cells (P=0.004) in the MI mouse models. In the isolated CD4+T cells, CPCsExos treatment significantly up-regulated the percentages of Treg (P=0.01) and CD4+IL-10+ T cells (P=0.004) and increased the expression of mTOR (P=0.009) and p-mTOR (P=0.009), and these effects could be further enhanced by the mTOR activator but obviously attenuated by the mTOR inhibitor. CPCs-Exos promotes the differentiation of Treg in mice with MI by modulating the mTOR signaling pathway.

The additive effects of nicotinamide mononucleotide and melatonin on mitochondrial biogenesis and fission/fusion, autophagy, and microRNA-499 in the aged rat heart with reperfusion injury.

The prognosis of myocardial ischemia/reperfusion (I/R) injury is poor in elderly patients. Aging increases the susceptibility of the heart to cell death from I/R injury and prevents the optimal effectiveness of cardioprotective modalities. Since the interaction of aging with cardioprotection is multifactorial, combination therapy may overcome the above-mentioned burden through correcting various components of the injury. Here, we explored the effects of nicotinamide mononucleotide (NMN)/melatonin combination therapy on mitochondrial biogenesis and fission/fusion, autophagy, and microRNA-499 in the aged rat heart with reperfusion injury. Ex vivo model of myocardial I/R injury was established by coronary occlusion and re-opening in 30 aged male Wistar rats (400-450g, 22-24months old). NMN (100mg/kg/48h, intraperitoneally) was administered over 28days before I/R, and melatonin (50µM) was added to the perfusion solution at early reperfusion. CK-MB release and expression of mitochondrial biogenesis genes and proteins, mitochondrial fission/fusion proteins, autophagy genes, and microRNA-499 were assessed. NMN/melatonin combination therapy concomitantly decreased CK-MB release in aged reperfused hearts (P < .001). It also upregulated SIRT1/PGC-1α/Nrf1/TFAM profiles at both gene and protein levels, Mfn2 protein, and microRNA-499 expression, and downregulated Drp1 protein and Beclin1, LC3, and p62 genes (P < .05 to P < .001). The effect of combination therapy was greater than individual ones. Co-application of NMN/melatonin within the setting of I/R injury in the aged rat heart induced noticeable cardioprotection through modulation of a coordinated network including microRNA-499 expression along with mitochondrial biogenesis associated with SIRT1/PGC-1α/Nrf1/TFAM profiles, mitochondrial fission/fusion, and autophagy, therefore, appears to prevent the burden of myocardial I/R injury in elderly patients.

Vitamin C alleviates LPS-induced myocardial injury by inhibiting pyroptosis via the ROS-AKT/mTOR signalling pathway

BackgroundThe efficacy of vitamin C in sepsis remains controversial. Whether vitamin C can alleviate lipopolysaccharide (LPS)-induced myocardial injury by inhibiting pyroptosis has not been studied. This study aimed to evaluate the effects of vitamin C on LPS-induced myocardial injury in vitro.MethodsH9C2 cells were treated with indicated concentrations of LPS, and the cell viability was then assessed by CCK-8 assay. The levels of lactate dehydrogenase (LDH), CK-MB, IL-18 and IL-1β were examined by enzyme-linked immunosorbent assay (ELISA). The levels of intracellular reactive oxygen species (ROS) were measured using the fluorescent probe dichlorodihydrofluorescein diacetate (DCFH-DA). Western blot assays were conducted to determine the levels of the ROS-associated protein nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) and pyroptosis-associated proteins, such as NOD-like receptor (NLR) family pyrin domain containing 3 (NLRP3), caspase-1 and gasdermin D (GSDMD). The AKT inhibitor MK-2206 was then applied to explore the signalling pathway. Finally, H9C2 cells were divided into the control group, LPS group, vitamin C + LPS group, and N-acetyl-l-cysteine (NAC) + LPS group. The intracellular ROS, levels of associated proteins, cell viability, and release of LDH, CK-MB, IL-18 and IL-1β were examined.ResultsLPS decreased cell viability and induced ROS and pyroptosis in H9C2 cells in a dose-dependent manner. Moreover, LPS activated the AKT/mTOR pathway in H9C2 cells. The AKT inhibitor MK-2206 protected H9C2 cells from LPS-induced death by suppressing pyroptosis, without changing intracellular ROS level. Vitamin C significantly inhibited intracellular ROS and cell pyroptosis in LPS-treated H9C2 cells. Moreover, vitamin C suppressed the activation of the AKT/mTOR pathway.ConclusionsOur data suggest that vitamin C alleviates LPS-induced myocardial injury by inhibiting pyroptosis via the ROS-AKT/mTOR signalling pathway and thus provide novel insights into the prevention of sepsis-induced myocardial dysfunction.

Del Nido versus conventional cardioplegia comparison in term of myocardial protection using cardiac enzymes in patients undergoing coronary artery bypass surgery

Introduction: Myocardial protection is the major component in cardiac surgery affecting the patient’s outcome (morbidity and mortality). The key components are cardiopulmonary bypass (CPB), hypothermia and the cardioplegia solution. Objective: To compare conventional vs Del Nido cardioplegias using Cardiac Troponin-I (CTnI) and CK MB release as the primary outcome variable in patients with preserved left ventricular ejection fraction undergoing coronary artery bypass surgery. Material and Methods: Retrospective comparative study conducted at Punjab Institute of Cardiology, cardiac surgery department. After informed consent, patients undergoing coronary artery bypass surgery were included in the study. Data was analyzed by comparing Del-Nido with Conventional Cardioplegia using CTnI and CKMB release as the primary outcome variable. Results: A total of 140 patients were divided in two groups 70 (50%) in Del-Nido group and 70 (50%) in conventional group. In Del Nido group the mean Cardioplegia volume given was 1271.43 ± 447.91 ml and in Conventional Cardioplegia mean volume given was 2142.86 ± 584.48 ml with p-value &lt;0.005. The comparison of Troponin I (ug/ml) levels post-operatively after 6, 9, 12 and 24 hours and on 5th day in Del Nido and conventional Cardioplegia groups showed insignificant p-values of 0.797, 0.977, 0.956, 0.496 and 0.297 respectively, which depicted that there is no remarkable difference in Troponin I levels regarding times in both groups. The comparison of CKMB (IU/L) levels in both groups after 6 hours 24 hours and on 5th day of CABG showed significant p-value of 0.032, 0.027 and 0.001 respectively and determined the difference in both groups. Whilst the comparison of CKMB (IU/L) levels post-operatively after 9 and 12 hours of CABG in both groups showed insignificant p-values of 0.706 and 0.476 respectively which implied that there is no major difference in CKMB levels regarding times in both groups. Conclusion: The key benefits of Del Nido cardioplegia, which makes it preferable to conventional cardioplegia, are less volume needed and an uninterrupted operation. While time related troponin I and CKMB levels changes showed almost similar results in both groups. So we can say both groups are equally safe and have same outcomes.

DJ-1 activates the AMPK/mTOR pathway by binding RACK1 to induce autophagy and protect the myocardium from ischemia/hypoxia injury

Myocardial Ischemic Injury is a serious threat to human health, and DJ-1 is involved in cardioprotection. The research intended to explore the effects and mechanism of DJ-1 to protect myocardium against ischemia injury. DJ-1 overexpression lentivirus vectors were transduced into the myocardium of SD rats and H9c2 cells, and an AMI model in vivo and a hypoxia model in vitro were established, respectively. Results showed that DJ-1 overexpression alleviated myocardial ischemia injury, as demonstrated by reduced the extent of myocardial infarction, improved cell survival, decreased LDH activity and CK-MB release. Furthermore, DJ-1 interacted with RACK1, activated AMPK/mTOR pathway, induced adaptive autophagy and protected the myocardium. However, RACK1 siRNA or compound C (an AMPK inhibitor) could weaken the above effect of DJ-1 on myocardium. In conclusion, DJ-1 could activate adaptive autophagy by the RACK1/AMPK/mTOR pathway and protect the myocardium against ischemia injury.

MiR-19b-3p regulated by BC002059/ABHD10 axis promotes cell apoptosis in myocardial infarction

BackgroundRecently, microRNAs (miRNAs), have been extensively investigated in diseases. The upregulated expression of miR-19b-3p has been validated in patients with hypertrophic cardiomyopathy. Nonetheless, it regulatory mechanism in myocardial infarction (MI) is still unclear.PurposeThis research aimed to investigate the role and molecular regulation mechanism of miR-19b-3p in MI.MethodsQRT-PCR and western blot assays measured RNA and protein expression. Cell apoptosis were tested by flow cytometry and TUNEL assays. Cell viability was measured by trypan blue staining method. RIP and luciferase report assays examined gene interaction. The assays were performed under hypoxia condition.ResultsMiR-19b-3p was highly expressed in myocardial cell line H9C2, primary cardiomyocytes, and tissues from MI mouse model. MiR-19b-3p inhibition suppressed the apoptosis of cardiomyocytes. BC002059 could up-regulate ABHD10 through sequestering miR-19b-3p. BC002059 upregulation was observed to repress cell apoptosis. Rescue experiments demonstrated that miR-19b-3p overexpression abrogated the suppressive impact of BC002059 on the apoptosis of MI cells, and infarct size, area at risk as well as CK-MB and LDH release of MI mouse model tissues, which was further abolished via ABHD10 increment.ConclusionMiR-19b-3p regulated by BC002059/ABHD10 axis promotes cell apoptosis in MI, which might provide a novel perspective for MI alleviation research.

Induction of P-glycoprotein expression by dandelion in tumor and heart tissues: Impact on the anti-tumor activity and cardiotoxicity of doxorubicin

BackgroundPreviously, we have investigated the anti-tumor activity and mechanism through which dandelion acts against triple-negative breast cancer (TNBC). However, traditional Chinese medicine is mostly accepted as an adjunct therapy during chemotherapy in clinical practice. So far, little is known about the effects of dandelion in conjunction with chemotherapeutic drugs. PurposeTo investigate the effects of dandelion on the anti-tumor activity and cardiotoxicity of doxorubicin (DOX), and to further explore the molecular mechanisms through which these effects occur. Study designAt the beginning of this study, dandelion was observed to alleviate DOX-induced cardiotoxicity and reduce the anti-tumor activity of DOX. Subsequently, we investigated whether the resistance to DOX mediated by P-glycoprotein was involved in the above effects. MethodsThe cardioprotective effect of dandelion was investigated on DOX-treated mice by histological analysis, myocardial enzyme assays, and an untargeted metabolomics study based on LC-Q-TOF/MS. TNBC cell lines and 4T1 tumor-bearing mice were employed to investigate the combined anti-tumor activity. Laser scanning confocal microscope and a flow cytometry analysis were employed to measure the intracellular accumulation of DOX. A specific, sensitive, and rapid LC–MS/MS method was developed to detect the efflux of DOX from cells. Expression of P-glycoprotein in mouse tumor and heart tissues was detected via Western blotting analysis. ResultsDandelion was found to significantly alleviate DOX-induced cardiotoxicity, as was evidenced by improved cardiomyocyte morphology, decreased LDH and CK-MB release, and adjusted metabolic biomarker levels. However, in vitro and in vivo studies showed that dandelion could reduce the anti-tumor activity of DOX. This counteraction was achieved by activating of the drug efflux transporter P-glycoprotein, thereby promoting the efflux of DOX from cells and reducing the intracellular accumulation of DOX. Moreover, the activation of P-glycoprotein by dandelion in mouse heart tissue was also observed, thus suggesting that the decrease of cardiac DOX accumulation plays an important role in the cardioprotective effect of dandelion. ConclusionDandelion can activate the P-glycoprotein in heart and tumor tissues, which ameliorates DOX-induced cardiotoxicity but attenuates DOX cytotoxicity toward TNBC. Our findings have important implications for the correct clinical use of dandelion.

Role of atrial natriuretic peptide in abrogated cardio protective effect of ischemic postconditioning in diabetic rat heart

Background: Diabetes decreased cardioprotective potential of ischemic postconditioning (IPOC), atrial natriuretic peptide (ANP) induced the cardioprotection against ischemic-reperfusion (I/R) injury. The present study has been designed to investigate the role of ANP induced postconditioning in diabetic rat heart. Methods: Isolated Langendorff perfused normal and diabetic rat hearts were stabilized for 10 min proceed by global ischemia further followed by four cycles of IPOC, each cycle comprised 5 min of reperfusion and 5 min of ischemia at onset of 120 min of reperfusion. Perfusion of ANP (0.1μM/l) with Krebs–Henseleit Buffer solution in isolated diabetic rat heart for four-cycle of IPOC significantly decreased I/R-induced myocardial infarct size and release of CK-MB and lactate dehydrogenase (LDH) level in coronary effluent. Results: Four cycles of IPOC-induced cardioprotection noted by decreased in infarct size and also in release of LDH and CK-MB in normal rat heart. However, IPOC-induced cardioprotection was completely attenuated in isolated heart obtained from diabetic rat. Perfusion of ANP (0.1μM/L) significantly restored the attenuated cardioprotection in diabetic rat heart, which was completely blocked by perfusion of L-NAME (100μM/L), an eNOS inhibitor. Conclusion: So that, ANP restored cardioprotective affect in diabetic rat heart, which was completely abolished by the perfusion of L-NAME (100μM/L), an eNOS inhibitor.

Cardioprotective action of aprepitant in a rat model of ischemia-reperfusioninduced myocardial injury: role of PI3K-AkT-GSK-3β-HIF-1α signaling pathway

The present study explored the role and mechanism involved in aprepitant-induced cardioprotective effects in rat model of ischemia-reperfusion injury. The isolated hearts of Wistar male albino rats were subjected to ischemia-reperfusion injury on Langendorff apparatus. The extent of myocardial injury was assessed by measuring lactate dehydrogenase 1 and CK-MB release in the coronary effluent. The rats were treated with aprepitant (5, 10 and 20 mg/kg) before isolating hearts. After injury, the levels of HIF-1α, p-AkT, p-GSK-3β/GSK-3β were measured in heart homogenates. LY294002 was employed as PI3K inhibitor. Ischemia-reperfusion led to significant myocardial injury and decreased the levels of HIF-1α, p-AkT and ratio of p-GSK-3β/GSK-3β. Aprepitant attenuated myocardial injury and restored the biochemical changes in a dose-dependent manner. Pre-treatment with LY294002 (10 and 20 mg/kg) abolished aprepitant-mediated cardioprotective effects and restored the biochemical parameters in the heart homogenate. Aprepitant may be effective in preventing ischemia-reperfusion-induced myocardial injury, which may be due to activation of PI3K-AkT-GSK-3β and HIF-1α signaling pathway.

Role of ACE and ACE-2 in abrogated cardioprotective effect of ischemic preconditioning in ovariectomized rat heart

Ischemic heart disease is the leading cause of death in postmenopausal women. The activity of heart ACE increases whereas the activity of ACE-2 decreases after menopause. The present study was designed to investigate the role of ACE and ACE-2 in the abrogated cardioprotective effect of IPC in OVX rat heart. The heart was isolated from OVX rat and mounted on Langendorff’s apparatus for giving intermittent cycles of IPC. The infarct size was estimated using TTC stain, and coronary effluent was analyzed for LDH, CK-MB, and nitrite release. IPC induced cardioprotection was significantly attenuated in the ovariectomized rat heart as compared to the normal rat heart. However, this attenuated cardioprotection was significantly restored by perfusion of DIZE, an ACE-2 activator, and captopril, an ACE inhibitor, alone or in combination noted in terms of decrease in myocardial infarct size, the release of LDH and CK-MB, and also increase in the release of NO as compared to untreated OVX rat heart. Thus, it is suggested that DIZE and captopril, alone or in combination restore the attenuated cardioprotective effect of IPC in OVX rat heart which is due to an increase in ACE-2 activity and decrease in ACE activity after treatment.

Effect of Shenfu Injection on Reperfusion Injury in Patients Undergoing Primary Percutaneous Coronary Intervention for ST Segment Elevation Myocardial Infarction: A Pilot Randomized Clinical Trial.

Background: Shenfu injection is a traditional Chinese medicine formulation that alleviates ischemia-reperfusion injury through multiple pharmacologic effects. However, no data are available regarding its efficacy in patients with myocardial infarction. We aimed to examine the effects of Shenfu injection on infarct size in patients with ST segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).Methods: From April 2016 to February 2018, 40 patients with first-time anterior STEMI undergoing primary PCI within 6 h of symptom onset were randomized 1:1 to intravenous Shenfu injection (80 ml Shenfu injection + 70 ml 5% glucose injection) or placebo (150 ml 5% glucose injection) before reperfusion. Treatment started before PCI and maintained for 5 days after PCI. The primary end point was infarct size assessed by CK-MB area under the curve (AUC) over 72 h and cardiac magnetic resonance (CMR) imaging 4 ± 1 days after PCI.Results: Infarct size by area under the curve for CK-MB over 72 h did not differ between the Shenfu injection and placebo groups (5602.5 [3539.4–7526.4] vs. 6403.2 [2234.4–8340.6] ng·h/ml, P = 0.82). Among 32 patients who underwent CMR Imaging, a nominal reduction in infarct size was observed in the Shenfu injection group compared with the placebo group (23.9 [15.2–28.5] % vs. 27 [21.9–31.9] %, P = 0.42). After excluding patients with no or minimal infarct, there was a trend toward reduction in infarct size in the Shenfu injection group (24.1 [20.3–29.3] % vs. 29.1 [24.5–32] %, P = 0.18). Incidence of adverse events was similar between the groups.Conclusions: This pilot study showed that the use of Shenfu injection was safe but did not reduce infarct size by CMR Imaging and CK-MB release kinetics in reperfused patients with STEMI. Larger studies (confining to patients with extensive infarct size) to evaluate the efficacy of Shenfu injection on reperfusion injury are warranted.Clinical Trail Registration: clinicaltrials.gov, identifier: NCT02709798.

Relationship between ablation index and myocardial biomarkers after radiofrequency catheter ablation for atrial fibrillation

BackgroundFurther in-vivo evidence is needed to support the usefulness of ablation index (AI) in guiding atrial fibrillation (AF) ablation. We aimed at evaluating the relationship between AI and other lesion indicators and the release of myocardial-specific biomarkers following radiofrequency AF ablation. MethodsForty-six patients underwent a first-time radiofrequency AF ablation and were prospectively enrolled in this study. Pulmonary vein isolation was performed by six experienced electrophysiologists with a point-by-point approach, guided by strict Visitag criteria and consistent AI target values. Myocardial-specific biomarkers troponin T and creatine kinase myocardial band were measured after 6 (TnT6 and CKMB6) and 20 h (TnT20 and CKMB20) following sheath removal. Ablation duration, impedance drop (ID), force-time integral (FTI) and AI were registered automatically and analyzed offline. ResultsTnT release was 985 ± 495 ng/L and 1038 ± 461 ng/L (p = ns) while CKMB release was 7.3 ± 2.7 μg/L and 6.5 ± 2.1 μg/L (p < 0.001) at 6 and 20 h respectively. Ablation duration, ID, FTI and AI were all significantly correlated with the release of myocardial-specific biomarkers both at 6 and 20 h. Ablation index showed the highest degree of correlation with TnT6, TnT20, CKMB6 and CKMB20 (Pearson's R 0.69, 0.69, 0.61, 0.64 respectively, p < 0.001). Multiple regression analysis demonstrated that AI had the strongest association with TnT6, TnT20, CKMB6 and CKMB20 (β 0.43, β 0.71, β 0.44 and β 0.43 respectively). ConclusionAblation index appears as the strongest lesion indicator as measured by the release of myocardial-specific biomarkers following radiofrequency catheter ablation for AF.

Sevoflurane Alleviates Myocardial Ischemia Reperfusion Injury by Inhibiting P2X7-NLRP3 Mediated Pyroptosis.

Myocardial ischemia is common in aging population. This study investigates the protective effect of Sevoflurane on myocardial ischemia reperfusion injury (MIRI) and its underlying mechanism. A total of 87 patients with a history of myocardial ischemia who underwent abdominal surgery with Sevoflurane general anesthesia were recruited in the study. The clinical data, blood pressure, heart rate, pressure-rate quotient (PRQ) and rate-pressure product (RPP) were recorded. Serum samples were collected and heart-type fatty acid binding protein (H-FABP), ischemia modified albumin (IMA), interleukin-1β (IL-1β), and interleukin-18 (IL-18) were measured to observe whether Sevoflurane anesthesia had protective effect on myocardium. In addition, MIRI rats and hypoxia/reoxygenation (H/R) injury cell model was established using neonatal rat ventricular myocytes (NRVM). Rats or NRVM were pretreated with sevoflurane for 45min before hypoxia. The mRNA expression of purinergic receptor-7 (P2X7) and NLR family pyrin domain containing 3(NLRP3) were examined. The protein expression of P2X7, NLRP3, apoptosis-associated speck-like protein (ASC), cysteine aspartic acid specific protease-1(Caspase-1), Gasdermin-D (GSDMD), Bcl-2 Associated X Protein (Bax), B-cell lymphoma-2 (Bcl-2) in myocardial tissue and cells were evaluated. The serum contents of IL-1β, IL-18, Malondialdehyde (MDA), Superoxide dismutase (SOD), Lactate dehydrogenase (LDH), Creatine kinase (CK), and Creatine kinase isoenzymes (CK-MB) were measured. The cellular localization and fluorescence intensity of NLRP3 and ASC in cells were detected. It was found that the secretion of IL-1β and IL-18 decreased in the patients. After I45 min/R3h in SD rats and H3h/R1h in NRVM, the protein expressions of P2X7, NLRP3, ASC, Caspase-1 and GSDMD were increased, the release of IL-1β, IL-18, CK, CK-MB, LDH and MDA were increased, and SOD activity was decreased. Sevoflurane treatment inhibited the high expression of P2X7, NLRP3, ASC, Caspase-1 and GSDMD, inhibited the release of LDH, CK,CK-MB and MDA in cells, and improved the activity of SOD, indicating that Sevoflurane alleviated the damage of MIRI of rats and H/R of NRVM, and had myocardial protective effect. Taken together, our study suggests that Sevoflurane inhibited the expression of IL-1β, IL-18 and GSDMD by inhibiting the P2X7-NLRP3 signaling pathway. It reduced the H/R injury of cardiomyocytes and protected the cardiac function by regulating inflammatory reaction and pyroptosis.

SMYD1 alleviates septic myocardial injury by inhibiting endoplasmic reticulum stress.

Sepsis-induced cardiomyopathy (SIC) is a major complication of sepsis. SET and MYND domain containing 1 (SMYD1) has central importance in heart development, and its role in SIC has not been identified. Herein, we found that the expression of SMYD1 was downregulated in myocardial tissues of SIC patients (from GEO database: GSE79962) and lipopolysaccharide (LPS)-induced SIC rats, and LPS-induced H9c2 cardiomyocytes. We used LPS-stimulated H9c2 cells that mimic sepsis in vitro to explore the function of SMYD1 in SIC. MTT assay, LDH and CK-MB release assay, flow cytometry, and ELISA assay showed that SMYD1 overexpression enhanced cell viability, alleviated cell injury, impeded apoptosis, and reduced the level of proinflammatory factors and NF-κB activation under the condition of LPS stimulation. Moreover, SMYD1 exerted protective effect on H9c2 cells stimulated with LPS through relieving endoplasmic reticulum (ER) stress. In conclusion, overexpression of SMYD1 alleviates cardiac injury through relieving ER stress during sepsis.

Cholecystokinin-mediated pharmacological preconditioning effects on ischemic rat hearts: Possible signaling pathways.

Cholecystokinin (CCK-8) has been shown to exhibit pharmacological preconditioning and cardioprotective effects. However, the molecular mechanisms involved in CCK-8-induced pharmacological preconditioning have not yet been clarified. The current study explored the molecular mechanisms involved in CCK-8-mediated pharmacological preconditioning effects on ischemic rat hearts. Pharmacological preconditioning was induced in male Wistar rats by administration of CCK-8 (20 μg/kg) 24 h before heart isolation. The PI3K inhibitor LY294002 (10 mg/kg and 20 mg/kg) and the HIF-1α inhibitor YC-1 (1 mg/kg and 2 mg/kg) were administered 30 min before the administration of CCK-8. The hearts were subjected to ischemia-reperfusion (IR) injury using a Langendorff apparatus. Myocardial injury was quantified by measuring the release of LDH-1, CK-MB and cTnT. The levels of HIF-1α and p-Akt expression and the ratio of p-GSK-3β/GSK-3β, were assessed in the heart homogenates. Pharmacological preconditioning with CCK-8 reduced IR-induced increases in the release of LDH, CK-MB and cTnT. Moreover, it restored the expression of HIF-1α and p-Akt, and the p-GSK-3β/GSK-3β ratio. However, administration of LY294002 or YC-1 with CCK-8 significantly abolished the cardioprotective effects of pharmacological preconditioning. The PI3K and HIF-1α inhibitors also abolished the effects of CCK-8 preconditioning on HIF-1α, p-Akt and p-GSK-3β/GSK-3β. Based on these findings, it may be concluded that the molecular mechanisms participating in CCK-8-induced pharmacological preconditioning involve HIF-1α, PI3K, Akt, and GSK-3β signaling pathways.

Association between ablation index and myocardial injury following radiofrequency catheter ablation for atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Unpredictable lesion formation is a major limiting factor for radiofrequency catheter ablation for atrial fibrillation (AF). Ablation index (AI) emerged as a novel parameter to monitor lesion development and potentially improve clinical outcomes. Additional evidence is needed to support its use. Purpose We aimed at evaluating the relationship between AI and other lesion indicators and the release of myocardial-specific biomarkers following AF ablation. Methods Forty-six patients with similar baseline characteristics underwent a first-time radiofrequency ablation for AF and were prospectively enrolled in this study. Pulmonary vein isolation was performed by six experienced electrophysiologists with a point-by-point approach, guided by strict Visitag criteria and consistent AI target values. Myocardial-specific biomarkers troponin T and creatine kinase myocardial band were measured after 6 (TnT6 and CKMB6) and 20 hours (TnT20 and CKMB20) following sheath removal. Ablation duration, impedance drop (ID), force-time integral (FTI) and AI were registered automatically and analyzed off-line. Since biomarkers release reflect the total amount of myocardial injury, our independent variables consisted of total ablation duration, total ID, total FTI and total AI. Results 97% of total ablation duration fulfilled pre-specified Visitag criteria. Mean application duration was 20.0 ± 3.5 s, mean contact force was 15.9 ± 4.2 g, mean maximum power was 35.3 ± 1.5 W. Troponin T release was 985 ± 495 ng/L and 1038 ± 461 ng/L (p = ns) while CKMB release was 7.3 ± 2.7 mcg/L and 6.5 ± 2.1 mcg/L (p &amp;lt; 0.001) at 6 and 20 hours, respectively. Ablation duration, ID, FTI and AI were all significantly correlated with the release of myocardial-specific biomarkers both at 6 and 20 hours (all correlations significant at p &amp;lt; 0.01 level, Fig. 1). Ablation index showed the highest degree of correlation with TnT6, TnT20, CKMB6 and CKMB20 (Pearson`s R 0.69, 0.69, 0.58, 0.64 respectively, p &amp;lt; 0.001). Multiple regression analysis demonstrated that AI had the strongest association with TnT6, TnT20, CKMB6 and CKMB20 (beta 0.43, 0.71, 0.41 and 0.43, respectively). Conclusion Ablation index appears as the strongest lesion size indicator as measured by the release of myocardial-specific biomarkers following radiofrequency catheter ablation for AF. Abstract Figure. Scatter plots and correlations

Rhein Activates Janus Protein Tyrosine Kinase2/Signal Transducer and Transcription Activation Factor3 Reduces Mitochondrial Oxidative Damage Caused by Myocardial Ischemia/Reperfusion Injury

Background: Rhein is a kind of lipophilic anthraquinone widely existing in herbal medicine. Here we aim to investigate whether Rhein can reduce the degree of myocardial ischemia/reperfusion injury and inhibit the development of oxidative stress, and elucidate the molecular mechanism of Rhein in protecting myocardial cells. Methods: The anti-oxidation and anti-apoptosis effects of Rhein were studied by using the primary myocardial cells of ischemia/reperfusion rat as the model of myocardial injury. Cell viability was detected by MTT, The level of LDH and CK-MB released by cardiomyocytes was measured by Colorimetric assay. The ROS was observed under microscope and the level of catalase and glutathione peroxidase were detected by enzymatic methods. The JAK2/STAT3 signaling pathway mediated by Rhein was observed by Western blot. Results: Compared with that of the SIR group, cell viability in the SIR and Rhein co-treatment groups increased significantly (P &lt; 0.001), the release of LDH and CK-MB decreased, the positive rate of ROS in cardiomyocytes decreased, and the concentration of catalase and glutathione peroxidase increased significantly (P &lt; 0.001). Besides, Rhein can activate JAK2/STAT3 signaling pathway. JAK2 siRNA can inhibit the JAK2/STAT3 signaling mediated by Rhein. The addition of Rhein can significantly increase the activity of mitochondrial superoxide dismutase (SOD) and reduce the MDA, which indicates that the oxidative damage of mitochondria induced by Rhein was significantly weakened. The mitochondrial functional changes induced by Rhein can be reversed by JAK2 siRNA. Conclusion: Our study shows that Rhein can reduce ROS in cardiomyocytes by JAK2/STAT3 signaling pathway activation, and effectively inhibit the apoptosis of cardiomyocytes, thus having a direct protective effect on cardiomyocytes under SIR.

Intralipid postconditioning in patients of cardiac surgery undergoing cardiopulmonary bypass (iCPB): study protocol for a randomized controlled trial

BackgroundIntralipid is a necessary fatty acid carrier that has been safely used as an energy supplier in the clinic. It has played an important role in rescuing the cardiac arrest caused by local anesthetic toxicity. In recent years, experimental studies have shown that intralipid postconditioning (ILPC) could reduce myocardial ischemic/reperfusion (I/R) injuries. Our research group has innovatively conducted a pilot randomized controlled trial (RCT), and the results showed that ILPC could reduce the release of cTnT and CK-MB, biomarkers of myocardial I/R injury, in valve replacement surgery. However, the potential effects of ILPC on the clinical outcome of adult cardiac surgery patients are unclear. Intralipid postconditioning in patients of cardiac surgery undergoing cardiopulmonary bypass (iCPB) trial is aimed to further study whether ILPC could improve short-term and long-term clinical outcome, as well as cardiac function in adult cardiac surgery patients.MethodsThe iCPB trial is an ongoing, single-center, prospective, double-blinded, large sample RCT. In total, 1000 adults undergoing cardiac surgery will be randomly allocated to either the ILPC group or the control group. The intervention group received an intravenous infusion of 2 mL/kg of 20% intralipid (medium-chain and long-chain fat emulsion injection C6~C24, Pharmaceutical) within 10 min before aortic cross-unclamping, and the control group received an equivalent volume of normal saline. The primary endpoints are complex morbidity of major complications during hospitalization and all-cause mortality within 30 days after surgery. The secondary endpoints include (1) all-cause mortality 6 months and 1 year postoperatively; (2) the quality of life within 1 year after surgery, using the QoR-15 questionnaire; (3) the postoperative cardiac function evaluated by LVEF, LVEDS, and LVEDD, and the myocardial injury evaluated by CK-MB, cTnT, and BNP; and (4) short-term clinical outcomes during hospitalization and total cost are also detailed evaluated.DiscussionThe iCPB trial is the first to explore ILPC on the clinical outcome of adult cardiac surgery patients. The results are expected to provide potential evidences about whether ILPC could reduce the morbidity and mortality and improve the cardiac function and quality of life. Therefore, the results will provide a rationale for the evaluation of the potentially clinically relevant benefit of intralipid therapy.Trial registrationChictr.org.cn ChiCTR1900024387. Prospectively registered on 9 July 2019.

Involvement of amylin B-H2S-connexin 43 signaling pathway in vascular dysfunction and enhanced ischemia-reperfusion-induced myocardial injury in diabetic rats.

The present study was designed to investigate the role of amylin, H2S, and connexin 43 in vascular dysfunction and enhanced ischemia–reperfusion (I/R)-induced myocardial injury in diabetic rats. A single dose of streptozotocin (65 mg/kg) was employed to induce diabetes mellitus. After 8 weeks, there was a significant decrease in the plasma levels of amylin, an increase in I/R injury to isolated hearts (increase in CK-MB and cardiac troponin release) on the Langendorff apparatus. Moreover, there was a significant impairment in vascular endothelium function as assessed by quantifying acetylcholine-induced relaxation in norepinephrine-precontracted mesenteric arteries. There was also a marked decrease in the expression of H2S and connexin 43 in the hearts following I/R injury in diabetic rats. Treatment with amylin agonist, pramlintide (100 and 200 µg/kg), and H2S donor, NaHS (10 and 20 μmol/kg) for 2 weeks improved the vascular endothelium function, abolished enhanced myocardial injury and restored the levels of H2S along with connexin 43 in diabetic animals. However, pramlintide and NaHS failed to produce these effects the presence of gap junction blocker, carbenoxolone (20 and 40 mg/kg). Carbenoxolone also abolished the myocardial levels of connexin 43 without affecting the plasma levels of amylin and myocardial levels of H2S. The decrease in the amylin levels with a consequent reduction in H2S and connexin 43 may contribute to inducing vascular dysfunction and enhancing I/R-induced myocardial injury in diabetic rats.